The present invention is directed to multiple ejector systems implementing a plurality of biofluid ejectors arranged to print biological assays.
Many scientific tests such as those directed to biology, genetics, pharmacology and medicine, employ sequences or arrays of biofluid drops upon which the tests are to be performed. In some testing applications up to several thousand biofluid drops are deposited onto a single substrate where a single substrate contains a variety of unique biofluids. For example, in current biological testing for genetic defects and other biochemical aberrations, thousands of the individual biofluids may be placed on a glass substrate at different locations. Thereafter, additional biofluids may be deposited on the same locations to obtain an interaction. This printed biological assay is then scanned with a laser in order to observe changes in a physical property.
In these situations it is critical that the drop ejection devices not be a source of contamination or permit cross-contamination between biofluids. Another consideration in the printing of biological assays is the high cost of the biofluids used in such experiments. It is therefore desirable to minimize the volume of biofluid required for generating a biological assay.
Existing mechanisms used to produce biological assays fall short in their ability to accurately place the biofluid drops such as to avoid contamination and cross-contamination. They also use larger volumes of biofluid than desirable, and use processes to form the biological assays which are time intensive.
It has therefore been considered desirable to develop multiple ejector systems which emit biofluids in a manner that avoids contamination and cross-contamination, uses small volumes of biofluids in the printing process, and has a high throughput which makes the printing of the biological assays highly efficient and economical.
A multiple-ejector system for printing arrays of biofluids include a tooling plate having a plurality of sets of tooling pins extending outward from the surface of the tooling plate. A printed circuit board is provided having pairs of power connection pins and ground return pins extending from a surface of the circuit board. A plurality of biofluid drop ejection units are provided and include alignment grooves and a transducer. Each of the plurality of biofluid drop ejection units are attached to a corresponding one of a set of tooling pins by connection of the tooling pins and alignment grooves. The power connection pins are placed in operational engagement with respective transducers, and the ground return connection pins are in operational engagement with a body portion of the drop ejection units. The drop ejection units contain different biofluids which are to be emitted onto a substrate. Verification of drop ejection units containing biofluids, may be obtained in one embodiment through the use of an optical scanner. Detection of drops at defined locations, provides a verification that validates a properly formed spot is present on a substrate, and is in the correct position.